Lua 4.0 undeclared variables and conditional statements

Question

This bit of code confuses me.

print(gogo) if (gogo == true) then print("yes") elseif (gogo == false) then print("no") end 

Why is gogo evaluating to true ? Should it not appear an error?

Answer 1

It does not evaluate to true and cannot, because in Lua 4.0 there is no boolean type.

 print(true) -- prints "nil" 

Undefined global nil variables by default, so really gogo == true . They are both nil .